<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>04_JS流程控制</title>
</head>
<body>
<script>
    console.log('1');
    console.log('2');
    console.log('3')

    let uname = "";
    if(!uname){
        alert('请先登录')
    }else{
        console.log('登录成功' + uname)
    }
    let gender = 100;
    switch (gender){
        case 1:
            console.log('男');
            break;
        case 2:
            console.log('女');
            break;
        default:
            console.log('未知性别');
    }
    let names = ['张三','李四','王五'];
    for(let i = 0; i < names.length; i++){
        console.log(names[i]);
    }
    console.log('循环结束');
    console.log(i);
    for(let n of names){
        console.log(n);
    }
</script>
</body>
</html>